This program project is concerned with the mode of action of hormones involved in reproductive processes. Progesterone receptors are being isolated from hen oviduct and their transformation concerned with nuclear binding is being studied. Purification of nuclear acceptors for sex steroid receptors has been undertaken and related to the structure of chromatin and specific nuclear events such as template capacity, activation of RNA polymerases and gene expression (ovalbumin mRNA). The guinea pig seminal vesicle epithelium is being studied with respect to androgen metabolism and specific protein synthesis. The receptor for luteinizing hormone is being studied in the rat corpus luteum and porcine granulosa cell with respect to purification, receptor induction and activation of adenylate cyclase. Spectrofluorometric techniques are being employed to study LH subunit interactions and LH receptor binding. Chemical modifications are being employed to determine the LH active site.